Steam engines



' (No Model.)

v H. DAVE Y.

7 METHOD OF AND APPARATUS FOR REGULATING STEAM ENGINES.

No. 247,619. Patented Sept. 27,1881.

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8 n 1 s Q I. fia/ev tan V Wife/eases. fliayjaygk UNITED STATES PATENT OFFICE.

HENRY DAVEY, OF LEEDS, COUNTY OF YORK, ENGLAND.

METHOD OF AND APPARATUS FOR REGULATING STEAM-ENGINES.

SPECIFICATION forming part of Letters Patent No. 247,619, dated September 27', 1881.

Application filed August 5, 1881. (No model.) Patented in England December 30, 1880.

To all whom it may concern:

Be it known that I, HENRY DAVEY, a citizen of England, residing at Leeds, in the county ofYork, England, have invented a new and useful Improved Method of and Apparatus for Regulating Steam-Engines, (for which I have obtained a patent in Great Britain, No. 5,489, bearing date December 30, 1880,) of which the following is a specification.

My invention relates to means of starting, stopping, reversing, and regulating the speed of large steam-engines by making them obey the movement of small or subsidiary engines, which can be easily handled and regulated. I will explain the means which I adoptfor this purpose as applied to a compound steam-engine, referring to the accompanying drawings.

Figure 1 is a plan, partly in section, and Fig. 2 is a transverse section through the crankshaft, showing, in side view, the double eccentrics which I employ and their connection to the slide-rods.

A and B are the high and low pressure cylinders, with their respective slides a and b.

In any convenient position near the main engine I provide a small subsidiary engine, 0, which may be of any known construction, hav ing a heavy fly-wheel, c, to keep its movement regular; or, if desired, having two cylinders working cranks at right angles to each other on one shaft, this form of engine being preferable whenthe main engine has occasionally to be reversed, as giving greater facility for reversal.

The crank-shaft s of the subsidiary engine 0 has fixed on it a pinion, g, gearing with a wheel, h, which is loose on the crank-shaft S of the main engine. To the wheel h are fixed two eccentrics, 0 0, and on the main shaft S are fixed other two eccentrics, a n. The pair of eccentricsn 0 in each case have their rods connected to a link or equal-armed lever, m, to the middle of which is jointed the slide-rod of the main engine.

In the eccentrics n n, 1 form curved slots, in which work studs k, projecting from the other eccentrics, 0 0, the slots being of the length of a quarter of a circle or thereabout. The

eccentrics n a being suitably set on the shaft S for working the main slides, if the eccentrics 0 0 take and maintain a position on the shaft corresponding therewith, the links at being in that case moved equablyat both ends by the eccentrics, their middles give the slides the proper extent of stroke in proper time. If, however, the main-engine shaft with its eccentrics n it should revolve more quickly than the eccentrics 0 o are driven by the subsidiary engine, then the eccentrics o 0 become shifted relatively to the eccentrics n a, and the links m being no longer moved equably at bothends their middles give lessened strokes to the main slides, thereby retarding the main engine until its speed is restored to that which is determined by the speed of the subsidiary engine G.

The slots that receive the studs lo operate as stops to prevent the eccentrics n 0 from departing more than ninety degrees from their relative setting. When the main engine is reversible the eccentrics n 02, instead of being fixed on the shaft, are driven by stops thereon, so that they can take a position suitable for either forward or backward motion.

From the arrangement described it will be seen that the starting or stopping of the subsidiary engine 0 determines that of the-main engine, and that by regulating the speed of the subsidiary engine by a governor or otherwise the speed of the main engine always bears the proportion to that of the subsidiary engine determined by the ratio of the gearing g h.

Having thus described the nature of my invention andthe best means I know of carrying it out in practice, I claim- 1. The herein-described method of regulating a main engine from a subsidiary engine by working the slide of the main engine by the middle of a link, the one end of which is worked from an eccentric on the main-engine shaft and the-other end of which is worked from an eccentric driven by the subsidiary en-' gine.

2. The combination of a subsidiary engine, (3, and an eccentric, o, driven by it, with an eccentric, a, driven by a main engine, and a link, m, connected to the main slide, substantially as and for the purposes herein set forth.

In testimony whereof I have signed my name to this specification, in the presence of two subscribing witnesses, this 18th day of July, A. D. 1881.

HENRY DAVEY.

Witnesses:

A. V. DOGKERY, CHAS. GILLIARD. 

